1. Field of the Invention
The present invention relates to a field weakening vector controlling method for permanent magnet synchronous motor and a control module.
2. Description of the Prior Art
As conventional technologies for vector-controlling in a field weakening region, Japanese Patent Laid-open No. Hei 08(1996)-182398 discloses a method of forming a table of d-axis current command values and controlling d- and q-axis currents proportionally and Japanese Patent Laid-open No. 2002-95300 discloses a method of obtaining a terminal voltage of a motor from d- and q-axis current controllers and calculating the d-axis current command value by proportional integration of a difference between the terminal voltage command value and the terminal voltage.